BBB, rCBF and glucose utilization (GU) were compared in gerbils during 5 minute cerebral ischemia and after recirculation. There was an increased permeability of the BBB shortly after release of the circulation and this was correlated with patches of hyperemia demonstrated in cCBF radioautography. Ten minutes after release of occlusion there was a pronouced hypoperfusion expressed in markedly reduced rCBF values. This was associated with conspicuous increase in glucose utilization in the hippocampus which lasted for 24 hours and then became greatly reduced when assayed at 48 hours. Secondary breakdown of the BBB was observed 3 days after release of occlusion in the hippocampus and this coincided with severe ischemic damage of the CA1 neurons.